Navel orange plant named Powell Late Navel

ABSTRACT

A new and distinct cultivar of navel orange plant, named Powell Late Navel, characterized by late maturing habits when grown in the inland citrus areas of New South Wales, Australia, and further characterized by its seedless deep orange fruit, the juice of which is characterized by the absence of the bitter taste associated with limionin levels which normally develop after navel oranges are juiced.

The invention comprises a new and distinct cultivar of navel orangeplant named Powell Late Navel.

The new cultivar is the result of a bud sport observed growing on a treein a planting of Valencia orange trees budded on to citrange root stocksby the inventor in 1979 in Curlwaa, New South Wales, Australia. The newcultivar was subsequently asexually reproduced by the inventor inCurlwaa, New South Wales, in 1982 by budding on to trifoliate rootstock. The resulting tree growth was medium to strong with no bud unionabornmalities being noted.

The new cultivar is particularly characterized by late maturing habitswhen grown in the inland citrus areas of southwest New South Wales,Australia. It is further characterized by the absence of the bittertaste associated with limionin levels which normally develop afternavels are juiced, even though the variety contains similar amounts oflimionin as Washington navels, namely, 7.3 to 11.6 ppm.

Taste testing of the juice from oranges produced by the new cultivar andstored in a refrigerator for at least five days after each monthlysample confirmed the absence of the bitter taste of off flavors. Furthercomparative taste tests were carried out using the juice of the PowellLate Navel and the varieties known as Washington Navel and Valenciaorange. These tests were carried out by a panel of six people in June,July, August, September, 1986. The order of preference of the panel isas follows, with the first being the most preferred, and the lastnumbered the least preferred:

1. Powell Late Navel juice 100%.

2. 50% of Powell Late Navel mixed with 50% of Washington Navel juice.

3. 50% of Powell Late Navel juice mixed with 50% Valencia juice.

4. Valencia juice 100%.

5. 50% Valencia juice mixed with 50% Washington Navel juice.

6. Washington Navel juice 100%.

The panel did not detect any off flavors or bitter taste in the firstfour selections. The fifth and sixth selections were both bitter and offflavored.

The fruit of Powell Late Navel is similar in many respects to the fruitof the cultivar known as Lane Late Navel. However, the rind color ofPowell Late Navel is more orange than the rind color of Lane Late Navel,and Powell Late Navel does not develop bitterness or off flavors late inthe season. In addition, the season for Powell Late Navel is longer, aswill be noted below.

The following description is based upon characteristics of the newcultivar, including produced fruit, as grown in Curlwaa, New SouthWales. Color references are to The Royal Horticultural Society ColourChart (R.H.S.), except where terms of ordinary dictionary significanceare used. The fruit was grown in 1986.

FIG. 1 is a color photograph comprising a front perspective view of atypical whole fruit of the new cultivar; and

FIG. 2 is a color photograph illustrating a typical cut section of fruitof the new cultivar.

Table 1, attached at the end of the specification, compares totalsoluble solids, citric acid, Brix°, and sugar to acid ratio for PowellLate Navel and the cultivar Lane Late Navel, throughout the 1986/1987season. Measurements in each case were carried out on ten fruit samplestaken on the date indicated, thereby allowing a standard deviationS.T.D. comparison to check the significant differences.

The dates set forth for Powell Late Navel indicate fruit taken from theoriginal orchard trees, except for the last three months where the fruitwas obtained from the first generation trees planted in November, 1982.

The dates set forth for the Lane Late Navel represent fruit taken fromthe original orchard tree discovered in 1952 by Mr. L. Lane. The seasonfor the Powell Late Navel in southwestern New South Wales is from Julyto March. The season for the Lane Late Navel in southwestern New SouthWales is from June to November.

Citrus Description

Tree: Medium to strong vigor, dense, spreading.

Leaves: Large (90 to 100 mm×50 to 60 mm); variable, lanceolate in formalthough somewhat variable; apex acute; base narrowed; edges distinctlycrenate, marginal oil cells many. Venation distinct. Petioles margined.Mature leaves glossy, dark on upper surface, pale to light green onlower surface. Texture smooth.

Fruit: Large, globose in form; base even; apex slightly depressed,sometimes broadly nippled but usually with large open navel; seedless.Average diameter 75 mm-85 mm, average weight 230-260 g.; rind pebbled,medium-thick (average 4.8 mm). Rind color, orange-deep orange,approximately 26A although color varies. Rind oil cells medium to large.The interior segments are usually 11 to 12 in number, with the segmentmembranes being thin and tough; pulp vesicles large, medium, long. Juiceabundant, evenly distributed in sections, flavor, rich, with acid andsugar well blended.

                  TABLE 1                                                         ______________________________________                                        Date of Sample                                                                          Powell Late Navel                                                                              Lane Late Navel                                    ______________________________________                                        Total soluble solids (kg/ton)                                                 5/13/86   41.03            --                                                 6/17/86   51.56            50.98                                              7/15/86   59.38            60.25                                              8/13/86   62.69            65.98                                              9/16/86   69.58            65.12                                              10/14/86  77.61            77.63                                              11/12/86  84.25            70.39                                              12/16/86  72.12            75.37                                              1/20/87   68.66            63.41                                              2/18/87   67.40            * no more                                          3/18/87   73.40            * fruit                                            4/24/87   46.30            * available                                        Citric acid (g/100 ml)                                                        5/13/86   1.47             --                                                 6/17/86   1.98             1.64                                               7/15/86   1.10             1.29                                               8/13/86   0.99             1.18                                               9/16/86   0.82             0.88                                               10/14/86  0.73             0.75                                               11/12/86  0.62             0.61                                               12/16/86  0.55             0.63 off                                                                      flavor                                             1/20/87   0.61             0.51 off                                                                      flavor                                             2/18/87   0.28             * no more                                          3/18/87   0.40             * fruit                                            4/24/87   0.38             * available                                        Brix°                                                                  5/13/86   9.6              --                                                 6/17/86   11.6             13.2                                               7/15/86   11.8             13.8                                               8/13/86   12.8             13.9                                               9/16/86   13.5             14.8                                               10/14/86  14.1             14.5                                               11/12/86  13.6             14.3                                               12/16/86  13.3             15.4                                               1/20/87   13.4             13.2                                               2/18/87   14.2             * no more                                          3/18/87   14.4             * fruit                                            4/24/87   10.2             * available                                        Sugar: acid ratio                                                             5/13/86   6.53             --                                                 6/17/86   5.85             8.04                                               7/15/86   10.72            10.69                                              8/13/86   12.93            11.78                                              9/16/86   16.46            16.82                                              10/14/86  19.32            19.33                                              11/12/86  21.94            23.44                                              12/16/86  24.18            24.44 off                                                                     flavor                                             1/20/87   21.97            25.88 off                                                                     flavor                                             2/18/87   50.70            * no more                                          3/18/87   36.10            * fruit                                            4/24/87   26.80            * available                                        Juice Percentage                                                              5/13/86   41.49            --                                                 6/17/86   43.00            37.68                                              7/15/86   49.40            42.85                                              8/13/86   48.26            46.66                                              9/16/86   50.94            43.47                                              10/14/86  54.46            52.99                                              11/12/86  61.39            48.81                                              12/16/86  53.78            48.55 off                                                                     flavor                                             1/20/87   50.79            46.97                                              2/18/87   47.30            x no more                                          3/18/87   50.70            x fruit                                            4/24/87   45.16            x available                                        ______________________________________                                    

We claim:
 1. A new and distinct variety of navel orange plant namedPowell Late Navel, as herein described and illustrated.